This invention relates generally to selecting content for presentation to users, and more specifically to selecting content for presentation in specific contexts relative to other presented content.
Various online systems provide content to client devices for presentation to online system users via one or more networks. An online system may select content for presentation to a user based on information about the user maintained by the online system. For example, an online system allows a user to establish connections between other users and to provide content to the online system, which provides the content to the other users connected to the user. The increasing popularity of online systems, and the significant amount of user-specific information maintained by online systems, allow users of an online system allows to easily communicate information about themselves to other users and share content with other users.
Additionally, entities may sponsor presentation of content items via an online system to gain public attention for the entity's products or services, or to persuade online system users to take an action regarding the entity's products or services. Many online systems receive compensation from an entity for presenting online system users with certain types of sponsored content items provided by the entity. Frequently, online systems charge an entity for each presentation of sponsored content to an online system user (e.g., each “impression” of the sponsored content) or for each interaction with sponsored content by an online system user (e.g., each “conversion”). For example, an online system receives compensation from an entity each time a content item provided by the entity is displayed to a user on the online system or each time a user is presented with a content item on the online system and the user interacts with the content item (e.g., requests additional content by interacting with the content item).
An online system may select content for presentation to users via the online system itself, for presentation by an application, or for presentation by a third party system other than the online system. If an application or a third party system requests content for presentation from the online system, the application or the third party system may provide information to the online system identifying a user of the online system to whom the application or the third party system presents the content. Based on the information identifying the user of the online system, the online system selects content for the user based on characteristics of the user maintained by the online system. However, when an application or a third party system requests content from the online system, the online system may be unable to identify an online system user to whom the application or the third party system is to present content. If the online system is unable to identify an online system user to whom the third party system or the application is presenting content, content the online system selects for presentation by the third party system or by the application may be less likely to be of interest to a user accessing the third party system or accessing the application, reducing interaction with content provided by the online system and reducing potential revenue to the online system.